Tapered loading of conductors



May 3, 1932.

J. J. GILBERT 1,856,702

TAPERED LOADING OF GONDUCTORS Filed April 25, 1930 /Nl/EN7'0R J J GILBERT l at ent ed May 3, 1932 UNITED STATES PATENT, OFFICE JOHN J. GILBERT, OF DOUGLASTON, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK TALPEREI) LOADING OF COND-UCTORS Application filed April 25,

This invention relates to inductively loaded signaling conductors, and in particular to long submarine cables.

The main object of the invention is to provide a new improved loaded signaling conductor and a new improved method of signaling over a metallic conductor. In accordance with this object, the invention in volves the inductive loading of a signaling conductor diflerently at different points along its length, and, in general, loading it most heavily in the central portion or portions carrying relatively light currents and more lightly on portions carrying larger currents. In some cases, the loading is reduced to zero at the terminals, that is, is omitted.

In one aspect of the invention, the grading of the inductive loading is such as to reduce attenuation as much as practicable to produce only small distortion in the received current. In another aspect, the grading is for the purpose of decreasing the sending voltage unbalance or, when such unbalance is not large, to permit the use of balancing networks which are less complicated than those heretofore used. From a different point of view, the invention comprises the grading of the loading of a signaling conductor in such manner as to enable the optimum permeability of the loading material to be maintained throughout the length of the loaded conductor. In still another aspect, the invention pertains to grading the loading of a submarine cable for the purpose of preventing or reducing distortion of the signals due to rapid variations of inductance caused by movement of the cable by ocean waves or currents. A specific object of the invention is the simultaneous accomplishment of two or more of these purposes to a marked degree by loading a signaling conductor differently at different points along its length.

This application is a continuation, in part, of applicants application Serial No. 696,981, filed March 5, 1924 which was a continuation in part of application Serial No. 57 9,393, filed August 3, 1922.

The present specification and the claims appended hereto relate to the particular method of tapered loading, disclosed, but not 1930. Serial No. 447,226.

specifically claimed in the applications mentioned in the preceding paragraph, which comprises tapering the loading by applying the material with a different angle of lay in different parts of the conductor. By this means one may vary the inductance, impedance, transmission efliciency, hysteresis loss or eddy-current loss of a unit length of conductor or any combination of these. In general this method of tapering the loading may be used in combination with a different thickness of loading material in different parts of the conductor, in combination with a material of different permeability in different parts of the conductor, in combination with material with the same permeability but different constancy of permeability in difierent parts of the conductor, or in general with any other method of tapering or varying the mag netic material along the conductor which appears to be necessary or advisable. V

This method has the general advantages of other methods and has the additional advantage that the angle of lay either of tape or wire may be varied by small increments and changed at frequent intervals along the conductor with very little difficulty in manufacturing. Furthermore, a relatively small change in the angle of lay may result in a fairly large change in inductance, and/or in the flux density existing in the magnetic loading material, for a given current flowing in the conductor.

A conductor in accordance with the invention is illustrated in the figure of the drawmg.

In the figure a conductor is shown in three sections 10, 11 and 12. On section 10 the single layer of loading material 13 is diagrammatically indicated as having a certain angle of lay, on section 11 a greater angle of lay, and on section 12 a still greater angle of lay.

When several layers of loading material are employed they may be wound either in the same or opposite directions and tapering may be accomplished by changing the angle of lay of all the layers at a particular point or by changing the angle of lay of diflerent layers at difierent successive points along the conductor. Furthermore, in a cable structure with four layers of tape, for example, the angle of lay of two layers may be changed at one point and of the other two layers at different points.

The principle of varying the lay is also applicable to loading material applied in wire form as well as in tape form, the term strand being used to include both wire and tape.

VVhatis claimed is:

1. A; signaling conductor havingthe inductance increased by the application of magnetic material, characterized in this, that the inductance, impedance, hysteresis loss,eddycurrent loss, or other characteristic of the conductor is changed from point to point along the conductor by applying the strand of magnetic loading material with an angle of different in different parts of the con-V ducto'r.

2. A cable according to-claim 1 having. a plurality of strands of magnetic material applied thereto, characterized in that the angle of lay of at least two strands in different layers has a different value at separated points along the conductor.

' 3. A continuously loaded signaling conductor having magnetic material spirally applied. thereto to increase the inductance in.

which the inductance is caused to have diflerent values per unit length in difierent sections (if the conductor by a spirally applied strand of magnetic material whose pitch and permeability both are difierent in said; different sections.

In witness whereof, I hereunto subscribe.

my name this 12th day of April, 1930.

JOHN J. GILBERT. 

